Image recording apparatus

ABSTRACT

An image recording apparatus has a recording head for recording an image on a recording medium, an ink supply source for supplying an ink to the recording head through an ink tube, a carriage for mounting the recording head thereon reciprocating in a primary scanning direction, and first and second guide members for supporting the carriage thereacross and guiding reciprocating movement of the carriage. The apparatus includes a scale provided on the second guide member along the primary scanning direction, a detector provided on the carriage for detecting a reciprocating position of the carriage in corporation with the scale, and a partition disposed in the vicinity of the scale for separating at least a part of the ink tube from the scale.

CROSS-REFERENCE OF RELATED APPLICATION

This non-provisional application claims priority under 35 U.S.C. §119(a)on Patent Application No. 2006-008303 in Japan on Jan. 17, 2006, theentire contents of which are hereby incorporated by reference.

BACKGROUND

The present invention relates to an image recording apparatus, which isprovided with a linear encoder for detecting a position and a movingrate of a carriage in the case of recording an image while reciprocatinga carriage having a recording head of an ink jet type mounted thereon ina direction orthogonal to a conveying direction of a recording medium.

As a conventional image recording apparatus, for example as disclosed inJapanese Patent Application Laid-Open No. H05-077514 (Refer to FIG. 1and FIG. 3) and Japanese Patent Application Laid-Open No. 2005-081691(Refer to FIG. 2, FIG. 3, and FIG. 4), a linear scale of on opticalsystem linear encoder extending along a primary scanning direction inorder to detect a position and a moving rate of a carriage having arecording head of an ink jet type mounted thereon has been well known.

In Japanese Patent Application Laid-Open No. 2005-081691 (Refer to FIG.2, FIG. 3, and FIG. 4), a guide shaft formed in a round shank forreciprocatably supporting a carriage to discharge ink drops toward alower side in a primary scanning direction and a shield plate forreciprocatably driving the carriage, which is longer than a belt forconveyance of a recording head in a horizontal direction, are arranged.A band-like scale (a tape scale) is extended so as to pass through anoptical sensor part provided on a side surface in a longitudinaldirection of the carriage, and the shield plate is arranged so as topartition the belt for conveyance of the recording head (a no-end belt)and the tape scale.

In addition, as shown in Japanese Patent Application Laid-Open No.2003-011340 (Refer to FIG. 1, FIG. 2, and FIG. 3), a printer apparatushaving an ink cartridge which is left at rest in a main body housing ofthe printer apparatus and connecting a carriage thereto by means of anink supply tube has been publicly known.

BRIEF SUMMARY

However, due to a minute ink drop injected from a recording head uponthe image recording operation, an ink mist (a misty floating ink)floating within the main body of the apparatus adheres to the linearencoder, so that accuracy of detection of a scale tends to be largelylowered.

For example, in Japanese Patent Application Laid-Open No. 2005-081691(Refer to FIG. 2, FIG. 3, and FIG. 4), since distances in height from aposition of a recording head up to a tape scale and an optical sensorpart are short, the ink mist easily adheres to the tape scale and theoptical sensor part and the accuracy of detection of the linear encoderis easily deteriorated.

The carriage in Japanese Patent Application Laid-Open No. 2005-081691(Refer to FIG. 2, FIG. 3, and FIG. 4) has the recording head on thelower surface side and an ink tank on the upper surface side. On theother hand, in Japanese Patent Application Laid-Open No. 2003-011340(Refer to FIG. 1, FIG. 2, and FIG. 3), the reciprocating carriage isconnected to the ink tank which is left at rest within the printerapparatus through an ink supply tube (an ink supply pipe) capable ofbeing curved (having a flexibility). In this case, even if a shieldplate is provided between the tape scale and the no-end belt forconveyance of the recording head, when the ink supply tube and the tapescale are arranged in proximity with each other, the curved portion ofthe ink supply tube scrapes against the surface of the tape scale andthe ink easily adheres to the surface of the tape scale. Accordingly,the accuracy of detection of the linear encoder is easily lowered ordeteriorated.

In order to solve the above-described problems, an object is to providean image recording apparatus, which is constituted so as to makeadhesion of the ink mist to the tape scale itself less and so as to becapable of reliably prevent lowering of the detection accuracy of thelinear encoder by preventing contact between the tape scale and the inksupply tube.

In order to attain the purpose, there is provided an image recordingapparatus according to an aspect, comprising: a recording head which canrecord an image on a recording medium; an ink supply source forsupplying an ink to the recording head through an ink tube; a carriagefor mounting the recording head thereon, which can reciprocate in aprimary scanning direction; first and second guide members forsupporting the carriage across the first and second guide members andguiding reciprocating movement of the carriage, wherein the second guidemember is arranged on the downstream side lower than the first guidemember in a subsidiary scanning direction orthogonal to the primaryscanning direction; a scale which is arranged on the second guide memberalong the primary scanning direction; a detector which is disposed onthe carriage, for detecting a reciprocating position of the carriage incorporation with the scale; and a partition which is arranged in thevicinity of the scale, for separating at least a part of the ink tubefrom the scale.

According to the aspect, when the carriage is moving along the primaryscanning direction, even if the ink supply tube is moved along withmovement of the carriage, the ink supply tube is merely brought intocontact with a partition wall. Thus, it does not prevent the smoothmovement of ink supply tube. Then, it has an advantage such that thesurface of the tape scale and the ink supply tube are not brought intocontact with each other because they are blocked by a partition wall;and the detection accuracy of the linear encoder is not deteriorated(lowered) when the ink adheres to the surface of the tape scale.

The above and further objects and features will more fully be apparentfrom the following detailed description with accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an image recording apparatus accordingto an embodiment;

FIG. 2 is a partial notch side cross sectional view of a recording part;

FIG. 3 is a plan view of a main body of the image recording apparatuswith an image reading part removed;

FIG. 4 is a plan view of the recording part with an upper cover bodyremoved;

FIG. 5 is a perspective view of the recording part with the upper coverbody removed;

FIG. 6 is an arrow diagram taken on a line VI-VI of FIG. 4;

FIG. 7 is a plan view of the recording part with the upper cover bodymounted thereon;

FIG. 8 is a partial notch enlarged perspective view of the recordingpart;

FIG. 9 is an arrow enlarged side cross sectional view taken on a lineIX-IX of FIG. 7;

FIG. 10 is an arrow enlarged side sectional view taken on a line X-X ofFIG. 7 for showing the cross section of the upper cover body;

FIG. 11 is an arrow side view taken on a line XI-XI of FIG. 4;

FIG. 12 is a left side view of a carriage;

FIG. 13 is a plan view of the carriage;

FIG. 14 is a bottom view of the carriage;

FIG. 15 is a partial notch explanatory view showing a connection stateof a timing belt; and

FIG. 16 is a perspective view of the recording part with the carriageremoved.

DETAILED DESCRIPTION

An image recording apparatus 1 according to an embodiment is an aspectof to a multi function device (MFD), which is provided with a printerfunction, a copy function, a scanner function, and a facsimile function.As shown in FIG. 1, on a bottom of a main body of a recording apparatus2 made of a synthetic resin of the apparatus, a sheet feeding cassette 3which can be inserted from an opening portion 2 a on the front side (theleft side in FIG. 1) of the main body of the recording apparatus 2 isarranged. Hereinafter, the side where the opening portion 2 a is locatedis referred to as a front side or a front portion and on the basis ofthis, the front side, right and left sides, and a rear side of theapparatus are determined.

According to the present embodiment, a plurality of sheets P as arecording medium which is cut into, for example, into an A4 size, aletter size, a legal size, and a card size is laminated (accumulated)and stored in the sheet feeding cassette 3 so that its shorter sideextends in a direction (a direction orthogonal to a paper surface, aprimary scanning direction, and an X axial direction in FIG. 1)orthogonal to a direction for conveyance of the sheet (a side scanningdirection, hereinafter, referred to as a Y axial direction) (refer toFIG. 1).

Further, on the front end of the upper portion of the sheet feedingcassette 3, a supplemental cassette 3 a for conveyance of a plurality ofsmall-size sheets (not illustrated) so as to be accumulated is mountedmovably in a Y axial direction. FIG. 1 shows the state that thesupplemental cassette 3 a is arranged at the position where thesupplemental cassette 3 a is not projected from the main body of therecording apparatus (a housing) 2 to the outside so as to be pressedinto there.

In addition, on the back side of the sheet feeding cassette 3 (on therear side in FIG. 1 and FIG. 2), a bank portion 8 for separating a sheetis arranged. Further, on the side of the main body of the recordingapparatus 2, an arm 6 a having its upper end capable of rotating in avertical direction is fitted. The sheet P is separated and conveyedone-by-one, which is the recording medium accumulated on the sheetfeeding cassette 3 and the supplemental cassette 3 a by a sheet feedingroller 6 provided on the lower end of this arm 6 a and an inclinedseparation plate 8. The separated sheet P is fed to a recording part 7which is provided on the upper side (the high position) backward of thesheet feeding cassette 3 via an upper lateral U-turn path (a sheetfeeding path) 9. The recording part 7 is formed by a carriage 5 or thelike capable of reciprocating, on which a recording head of an ink jettype 4 for realizing a printer function or the like is mounted, asdescribed later.

A sheet discharge part 10, on which the sheet P recorded by therecording part 7 is discharged with its recording surface turned around,is formed on the upper side of the supplemental cassette 3 a, and asheet discharge port 10 a communicated with the sheet discharge part 10(the upward of the opening portion 2 a) is opened toward the frontsurface of the main body of the recording apparatus 2.

On the upper part of the main body of the recording apparatus 2, animage reading apparatus 12 for reading an original or the like in a copyfunction and a facsimile function is arranged.

On the upper side of the main body of the recording apparatus 2, anoperation panel part 14 provided with various operational buttons and aliquid crystal display unit or the like is provided on the upper side ofthe image reading apparatus 12. The recording part 7, sheet dischargepart 10, and an ink storage part 15 provided on one side of this sheetdischarge part 10 are arranged so as to be located within a planar viewprojection area between the image reading apparatus 12 and the operationpanel part 14.

On the upper surface of the image reading apparatus 12, a glass platefor mounting (not illustrated) is provided, which can mount the originalthereon opening a document cover body 13 upward. On the lower side ofthe glass plate, an image scanner for reading the original (CIS: ContactImage Sensor) (not illustrated) is provided so as to be capable ofreciprocating in a direction orthogonal to the paper surface of FIG. 1(namely, a primary scanning direction, hereinafter, referred to as an Xaxial direction, and an axis extending in the primary scanning directionis referred to as an X axis).

The ink storage part 15 is released upward of the main body of therecording apparatus 2. In the ink storage part 15, an ink cartridge 19shaped in an approximately rectangular box with a small area in a planarview and a high measurement to store each of four inks for recording infull colors can be stored along a Y axial direction into one line(reference numerals 19 a to 19 d are given to cartridges for respectivecolors, namely, Black (BK), Cyan (C), Magenta (M), and Yellow (Y), seeFIG. 3). The ink storage part 15 is constituted so that the inkcartridge 19 can be attached or detached from above thereof.

Then, ink is supplied from each ink cartridge 19 (represented byreference numerals 19 a to 19 d, individually) to the recording head ofthe ink jet type 4 via a plurality (four in the present embodiment) ofink supply tubes (ink tubes) 20 (represented by reference numerals 20 ato 20 d, individually, and refer to FIG. 4 and FIG. 5). Further, in thecase of using more ink colors than four (six to eight colors or thelike), the ink cartridge in response to the number of the ink color maybe configured so as to be capable of being stored in the ink storagepart (ink supply source) 15 and the ink supply tube 20 may be increasedin response to the number of the ink cartridge.

As shown in FIGS. 3 to 16, the recording part 7 is supported by a pairof right and left side plates 21 a and 21 b in a frame-like main frame21 with its upper surface released. This recording part 7 is providedwith a horizontally-long platy first guide member 22 extending in the Xaxial direction (the primary scanning direction); a second guide member23; a carriage 5 which is configured so as to be capable ofreciprocating as being slidably supported across these both guidemembers 22 and 23; a timing belt (a no-end belt) 24 which is arranged onthe upper surface of the second guide member 23 in parallel with theupper surface for reciprocating the carriage 5 on which the recordinghead 4 is mounted; a CR (carriage) motor 25 for driving this timing belt24 (according to the embodiment, the CR motor 25 is a DC motor, however,other motor such as a stepping motor may be available); a platy platen26 for supporting the sheet P to be conveyed at the lower surface sideof the recording head 4; and a tape scale 47 which is a component of anoptical linear encoder for detecting a position of the X axial direction(the primary scanning direction) of the carriage 5 and a moving rate ofthis direction arranged so as to extend along the primary scanningdirection or the like. Further, on the upstream side of a sheetconveying direction (a direction of an arrow A, refer to FIG. 3, FIG. 4,and FIGS. 9 to 11) in a direction through which the sheet P passes onthe platen 26, the first guide member 22 is arranged, and on thedownstream thereof, the second guide member 23 is arranged.

The second guide member has a portion (an extension portion) including ahorizontal wide chip 23 a, which extends from an elongated portionincluding a guide chip 23 c into a downstream in a subsidiary scanningdirection. The horizontal wide chip 23 a is a flat shape. A portionincluding the horizontal wide chip 23 a (the extension portion) may beformed separately from a portion including the guide chip 23 c of thesecond guide member, and the both portions may be fixed with each otherby adhesion, welding, and screwing or the like.

In addition, as shown in FIG. 12 and FIG. 13 and to be described later,on the lower surface of the carriage 5 (a holder body 61), one fistsliding convex portion 55 a and a pair of right and left second slidingconvex portions 55 b are arranged on respective apexes of a triangle soas to bridge over the first guide member 22 and the second guide member23; the fist sliding convex portion 55 a abuts against a first slidingsurface 51 in the first guide member 22; and a pair of second slidingconvex portions 55 b abuts against a second sliding surface 52 in thesecond guide member 23. Further, a pair of right and left second slidingconvex portions 55 b is symmetrically provided at a distance for ameasurement X1 across a center line OX in the X axial direction of theholder body 61 (refer to FIG. 13). Accordingly, in a planar view of thecarriage 5 (or in a bottom view), a shape connecting respective centerparts of one fist sliding convex portion 55 a and a pair of right andleft second sliding convex portions 55 b is made into an isoscelestriangle.

On the other hand, the lower surface sides of the first guide member 22and the second guide member 23 extending along the primary scanningdirection (the X axial direction) are connected by a par of side plates21 a and 21 b extending in a subsidiary direction (the Y axialdirection). Then, in order to enlarge a movable range in the X axialdirection, furthermore, a recordable area in the X axial direction ofthe sheet P as much as possible while enlarging an interval in the Xaxial direction of the pair of right and left second sliding convexportions 55 b (2X1), at least one side portion of the second guidemember 23, preferably, the both end portions (according to theembodiment, right and left sides shown in FIG. 4 and FIG. 5) areelongated to the outside along the X axial direction above the sideplates 21 a and 21 b. As a result, when the carriage 5 is located at aleft end of the recording part 7 (namely, an ink receiver 48 to bedescribed later), the second sliding convex portions 55 b at the leftside in the carriage 5 can be located at a left end portion of thesecond guide member 23 above the left side plate 21 a.

In addition, a pair of resist rollers 27 is arranged on the upstreamside of conveyance across the platen 26 to convey the sheet P into a gapbetween a nozzle surface on the lower surface of the recording head 4and the platen 26. On the downstream side of the platen 26, a spur 28 bcontacting the upper surface of the sheet P and a sheet discharge roller28 a driven on the lower surface side are arranged and the recordedsheet P is conveyed to the sheet discharge part 10.

Further, as described above, in order to reduce the width measurement ofthe main body of the recording apparatus 2 while enlarging the movablerange in the X axial direction of the carriage 5, the positions of thecomponents arranged on one side or the opposite sides in the X axialdirection of the main frame 21 are devised. According to the embodiment,as shown in FIGS. 4 to 6 and FIG. 8, a driving shaft (not illustrated)of a driving motor 31 for conveyance of a sheet, which is fixed on theinner surface of a left side plate 21 a, is projected to the outersurface of the left side plate 21 a. A motive energy is transmitted froma pinion gear 32 a attached to this driving shaft to a firsttransmission gear 32 b which is directly linked to a driving roller 27 aof the pair of the resist rollers 27 in a concentric manner. The drivingroller 27 a is provided with a rotary encoder detection disk 33 with alarge diameter, and the upper part of the rotary encoder detection disk33 is projected from the upper surface of the left side plate 21 a tothe upper side. A no-end timing belt 35 c is winded around a firstpulley 35 a which is directly linked to a middle gear 34 engaged withthe first transmission gear 32 b in a concentric manner and a secondpulley 35 b which is attached to the sheet discharge roller 28 a.Further, reducing the diameter of the second pulley 35 b as compared tothe conventional one, the second pulley 35 b is stored in a spacebetween the outer surface of the left side plate 21 a and the lowersurface side of the second guide member 23 and the measurement in ahorizontal direction of the entire recording part 7 is reduced.

In addition, on the outside of the width of the sheet P to be conveyed(the shorter side of the sheet P), the ink receiver 48 is arranged onone end side of the recording part 7 (according to the embodiment, theregion near the left side plate 21 a in FIG. 3 and FIG. 4), and amaintenance unit 50 is arranged on other end side (according to theembodiment, the region near the right side plate 21 a in FIG. 3 and FIG.5), respectively. Thereby, the recording head 4 may discharge the inkfor periodically preventing clogging of a nozzle during the recordingoperation on a flashing position which is provided in the ink receiver48 and the ink receiver receives the ink. On the part of the maintenanceunit 50, the carriage 5 is located on a waiting position to carry outthe recovery processing or the like for selectively absorbing the inkfor each color and removing air bubbles within a buffer tank (notillustrated) on the recording head 4. In addition, a wiper (notillustrated) is provided in the maintenance unit 50 and cleaning of thenozzle surface of the recording head 4 is carried out when moving thecarriage 5 from the portion of the maintenance unit 50 into an imagerecording area direction.

The first guide member 22 at the upstream side in the sheet conveyingdirection (an arrow A direction) and the second guide member 23 at thedownstream side are arranged approximately in a horizontal condition,respectively. As shown in FIGS. 9 to 11, in the side cross section ofthe first guide member 22, a plate portion 22 a having the first slidingsurface 51 for slidably supporting the region at the upstream side in asheet conveying direction (the arrow A direction) of the carriage 5 in ahorizontal condition and a projecting chip 22 b having a Z-shaped sidesurface which is fitted in an engagement concave portion 70 on theregion at the upper stream side in the sheet conveying direction in theholder body 61 to be described later of the carriage 5 are integrallyformed.

As shown in FIGS. 4 to 6, FIGS. 9 to 11, and FIG. 15, the side crosssection of the second guide member 23 is provided with the timing belt24; a CR (carriage) motor 25; a horizontal wide chip 23 a which is areference surface in a vertical direction (a Z axial direction) forattaching the tape scale 47 or the like; a plate portion 23 b having thesecond sliding surface 52 for slidably supporting the region at thedownstream side in the sheet conveying direction of the carriage 5across this horizontal wide chip 23 a in a horizontal condition; andapproximately a vertical guide chip 23 c which is flexed upward on theregion at the upstream side in the sheet conveying direction across thehorizontal wide chip 23 a.

The first sliding surface 51 in the first guide member 22 and the secondsliding surface 52 in the second guide member 23 are formed on the uppersurface of respective guide members 22 and 23 so as to be parallel withthe lower surface of the recording head 4 of the carriage 5 (namely, thenozzle surface having a nozzle formed thereon). On the guide chip 23 c,a third sliding surface 54 facing to the downstream side for conveyanceof the sheet is formed (refer to FIG. 4 and FIG. 5). The first, second,and third sliding surfaces 51, 52, and 54 are linearly formed so as tobe longer in the X axial direction, respectively.

As shown in FIGS. 11 to 13, the carriage 5 is formed by the holder body61 made of a synthetic resin, which is shaped in an approximatelyrectangle in a planar view, and a head storage part 61 a with a largedownward height measurement having the recording head 4 stored in itslower surface side is formed on the region at the upstream side forconveyance of the sheet of the holder body 61. On the region at thedownstream side for conveyance of the sheet of the holder body 61, anink flowing path (not illustrated) for supplying an ink to the recordinghead 4 with the front ends of the plurality of ink supply tubes 20 a to20 d transversely connected thereto, a connection support part 61 b forconnecting the front end of a flexible flat cable 40, and a guide groove85 used for a sensor (a photo-coupler) of an optical penetration system61 c for detecting a position and a moving rate by allowing a tape scale47 to be described in detail later to pass there through are integrallyprovided.

On the region at the upstream side for conveyance of the sheet of thecarriage 5, one fist sliding convex portion 55 a projected from itslower surface side and abutting against the first sliding surface 51 inthe first guide member 22 is provided on the center part in the Xdirection of the holder body 61 (refer to FIGS. 11 to 13).

On the region at the downstream side for conveyance of the sheet of thecarriage 5 (the holder body 61), the pair of right and left secondsliding convex portions 55 b projected from its lower surface side andabutting against the second sliding surface 52 in the second guidemember 23 is symmetrically provided at a distance for a measurement X1across a center line OX in the X axial direction of the holder body 61(refer to FIGS. 11 to 13 and FIG. 15). Accordingly, in a plan view ofthe carriage 5 (or in a bottom view), a shape connecting respectivecenter parts of one fist sliding convex portion 55 a and the pair ofright and left second sliding convex portions 55 b is made into anisosceles triangle. According to this constitution, the carriage 5 isstably supported by the first and second guide members 22 and 23.

A first subsidiary sliding convex portion 56 a provided in adjacent tothe fist sliding convex portion 55 a is configured so as to project agap (a paper gap) PG between the nozzle surface of the cap and theplaten 26 selectively downward from the lower surface of the fistsliding convex portion 55 a in the case of making the gap PG larger thanthe case that the first subsidiary sliding convex portion 56 a abutsagainst the fist sliding convex portion 55 a. In the same way, a secondsubsidiary sliding convex portion 56 b provided in adjacent to the pairof the second sliding convex portions 55 b is configured so as toproject the gap (the paper gap) PG between the nozzle surface of the capand the platen 26 selectively downward from the lower surface of thesecond sliding convex portion 55 b (refer to FIG. 10, FIG. 11, and FIG.13). Further, the carriage 5 is provided with a mechanism forselectively elevating the first subsidiary sliding convex portion 56 aand the second subsidiary sliding convex portion 56 b (its detailedexplanation is herein omitted) and their operational chips 57 a and 57 bare provided in the X axial direction so as to be capable ofreciprocating and rising and falling. This is a constitution toselectively elevating the first subsidiary sliding convex portion 56 aand the second subsidiary sliding convex portion 56 b by crashing theoperational chips 57 a and 57 b against cut-out chips 22 b and 23 d ofthe first guide member 22 and the second guide member 23 on one movingend and other end of the carriage 5 when the carriage 5 moves along theX axial direction (refer to FIG. 4, FIG. 5, FIG. 8, FIG. 9, FIG. 10, andFIG. 13 or the like).

In the carriage 5 (the holder body 61), a pair of right and left thirdsliding convex portions 60 a and 60 b (equivalent to one pair of slidingconvex portions in Claims) to be abutted against the third slidingsurface 54 in the second guide member 23 is integrally formed. In otherwords, the pair of right and left third sliding convex 60 a and 60 b issymmetrically provided at a distance for a measurement X2 across thecenter line OX in the X axial direction of the holder body 61 in FIG.14.

Further, in the carriage 5 (the holder body 61), assuming that a pair ofright and left fourth sliding convex portions 65 a and 65 b (equivalentto other pair of sliding convex portions in Claims) is arranged on therear surface side across the guide chip 23 c in a vertical direction,and this pair of fourth sliding convex portions 65 a and 65 b is formedon the opposite ends of a picking body 62 as a horizontally longitudinalelastic member made of a synthetic resin (refer to a part given a shadowline in FIG. 13). In FIG. 13, the pair of fourth sliding convex portions65 a and 65 b is arranged on a symmetric position at a distance for ameasurement X3 across the center line OX in the X axial direction of theholder body 61 (X3<X2<X1).

As shown in FIG. 14, right and left center parts of the picking body 62are attaching parts 62 a to the holder body 61 and a linking part 62 cwith a small cross section having flexibility by itself is formedbetween expansion parts 62 b on the right and left opposite ends. Withinrespective expansion parts 62 b, the fourth sliding convex portions 65 aand 65 b including a compression coil spring are arranged, and due abias force of this compression coil spring, the guide chip 23 c issandwiched between the picking body 62 and the third sliding convexportions 60 a and 60 b to be elastically supported. Further, a spacebetween picking body 62 and the third sliding convex portions 60 a and60 b is opened in the primary scanning direction (the X axial direction)and a lower direction (the Z axial direction) (refer to FIG. 10, FIG.11, and FIG. 13).

On the lower surface side of the carriage 5 (the holder body 61), a beltconnecting part 63 to which the timing belt 24 is partially connected isprovided between the second sliding convex portion 55 b and the thirdsliding convex portion 60 a (60 b) in a subsidiary scanning direction(the Y axial direction) (refer to FIG. 10, FIG. 11, and FIG. 13). Morespecifically, the belt connecting part 63 has a groove, which isdisposed on the lower surface side of the connection support part 61 b,is opened on the lower surface side of the carriage 5 and in theopposite directions of the primary scanning direction, and in which thetiming belt 24 is fitted.

A driving pulley 89 and a driven pulley 90 for winding the timing belt24 there around are arranged on the opposite ends in the primaryscanning direction on the upper surface side of the horizontal wide chip23 a in the second guide member 23 as shown in FIG. 3, FIG. 4, FIG. 5,and FIG. 14 (however, in FIG. 4 and FIG. 5, only the driven pulley 90 isshown). Thus, the second guide member 23 can carry out both functions,namely, slidably supporting of the carriage 5 and attaching means suchas the driving pulley 89, the CR motor 25, and the driven pulley 90 soas to be enable to reduce a cost. Further, it is possible to reduce thesizes of the recording part 7 and the image recording apparatus 1.

Further, the second guide member has a portion (an extension portion)including the horizontal wide chip 23 a, which extends from theelongated portion including the guide chip 23 c into the downstream inthe subsidiary scanning direction. The horizontal wide chip 23 a is aflat shape. A portion including the horizontal wide chip 23 a (theextension portion) may be formed separately from the portion includingthe guide chip 23 c of the second guide member, and the both portionsmay be fixed with each other by adhesion, welding, and screwing or thelike.

Further, the largest diameter D1 of the driving pulley 89 fitted on thedriving axis 25 b which is projected from a neck portion 25 a of acarriage motor (a CR motor) 25 is formed to be smaller than a diameterD2 of the neck portion 25 a (refer to FIG. 14). Then, with the drivingpulley 89 fitted and fixed to the driving axis 25 b in advance, thedriving pulley 89 and the neck portion 25 a are inserted into anattaching hole (equal to a diameter D2 of the neck portion 25 a) whichis formed on the horizontal wide chip 23 a in the second guide member 23from the lower side. In the second place, the driving motor 25 is fixedby a screw (not illustrated) from the upper surface of the horizontalwide chip 23 a.

Thus, forming the largest diameter D1 of the driving pulley 89 smallerthan the diameter D2 of the neck portion 25 a and forming an attachinghole 23 b, which is approximately equal to the diameter D2 of the neckportion 25 a, to the second guide member 23, the driving pulley 89 canbe fitted to the driving axis 25 b before attaching the driving motor 25to the second guide member 23. In addition, only the attaching hole forattaching the driving motor 25 may be formed on the horizontal wide chip23 a of the second guide member 23, so that a mechanical strength of thesecond guide member 23 is not weakened extremely. Further, as comparedto the attaching structure such that the horizontal wide chip 23 aarranged between the neck portion 25 a and the driving pulley 89 isarranged, the driving pulley 89 can be arranged very close to the neckportion 25 a. If a tooth surface (a tooth die) 89 a for the timing belt24 is formed on a circumferential surface of the driving pulley 89, noslip phenomenon is generated between the rotation of the driving motor25 and the movement of the timing belt 24. In addition, on the upper endside of the driving pulley 89, a flange portion 89 b for preventingdetachment of the timing belt 24 is integrally formed.

The driven pulley 90 is formed in such a manner that a pulley portion 90a for winding the timing belt 24 there around, a shaft portion 90 bwhich is projected from this pulley portion 90 a to the both directionsalong the rotational center line, and a flange portion 90 c with a largediameter which does not detach the opposite edges in the width directionof the timing belt 24 to the direction of a shaft portion 90 b areintegrally made by a synthetic resin material (refer to FIG. 14). Then,a holder 92 rotatably supporting the driven pulley 90 is elasticallybiased by a spring (not illustrated) in a direction separated from thedriving pulley 89.

If the arrangement position between the driving pulley 89 and the drivenpulley 90 is biased so that the shortest distance from the axial core(the rotational center) of the driving pulley 89 up to the guide chip 23c is smaller (shorter) than the shortest distance from the axial core(the rotational center) of the driven pulley 90 up to the guide chip 23c so as to allow an extension direction of the side chip which isconnected and fixed to the carriage 5 in the timing belt 24 wounded(bridged) around the driving pulley 89 and the driven pulley 90 to beapproximately in parallel with the guide chip 23 c in a verticaldirection in the second guide member 23, when the carriage 5 moves inthe primary scanning direction (the X axial direction), the carriage canbe pulled by the timing belt 24 so as to be in parallel with the guidechip 23 c and the carriage can safely move along the third slidingsurface 54 (the reference surface) in the guide chip 23 c. As a result,a recording performance of an image can be improved. In this case, byarranging the driven pulley 90 with a large diameter so as to beseparated from the guide chip 23 c, the width measurement of the secondguide member 23 in the direction of the arrow A can be made smaller, sothat the size of the apparatus can be reduced.

Further, it is preferable that the arrangement relation of the beltconnecting part 63 of the carriage 5 with respect to the driving pulley89, the driven pulley 90, and the timing belt 24 is determined so thatthe carriage 5 with the force component of the tension by the timingbelt 24 on the side attaching the carriage 5 is to act in directionpressing both plain plate 23 of the second guide member 23 and the guidechip 23 c as the vertical chip. Thereby, the movement of the carriage 5is stable as described later.

Therefore, since the carriage 5 is pressed against the guide chip 54which is a vertical chip of the second guide member 23, the shortestdistance of the belt connecting part 63 of the carriage 5 for the timingbelt 24 to the driving pulley 89 and the driven pulley 90 for the thirdsliding surface 54 in the guide chip 23 c is determined so as to belarger than the shortest distance on the winding portion of the timingbelt 24. If the apparatus is configured in this way, due to a componentforce in the Y axial direction which is orthogonal to the X axialdirection in which the guide chip 23 c is elongated among tension forcesF for the timing belt 24 in the belt connecting part 63, the carriage 5is pressed against the third sliding surface 54 in the guide chip 23 clocated on the arrangement side of the timing belt 24. Therefore, aposture of the carriage 5 during movement is stable and a recordingperformance of an image is improved.

On the other hand, FIG. 15 shows an embodiment for pressing and biasingthe carriage 5 against the second sliding surface 52 on the uppersurface of the horizontal wide chip 23 a of the second guide member 23.The height position of the belt connecting part 63 of the carriage 5 forthe timing belt 24 is biased to the upper side from the height positionof the region where the timing belt 24 is winded around the drivingpulley 89 and the driven pulley 90. In this case, at the belt connectingpart 63, a lower edge of the timing belt 24 fitted and sandwichedbetween blocks 63 a and 63 b is engaged downward so as not to drop offby a pair of engagement nail portions 63 c projected to the oppositesides of the lower end of the block 63 b. Then, the upper edge of thetiming belt 24 is regulated upward by the flange portion 89 b at theupper end of the driving pulley 89 so as not to drop out and further,the flange portion 90 c in the driven pulley 90 also regulates the upperedge of the timing belt 24 upward so as not to drop out.

According to the present embodiment, a barycentric position G of theentire carriage 5 is located on the center line OX in the X axialdirection shown in FIG. 14 in the X axial direction (in a right and leftwidth direction of the carriage 5) and as shown in FIG. 11, thebarycentric position G of the entire carriage 5 is located on the sideof the head storage part 61 a in the carriage 5 and on the position witha short distance at the distance Y1 along the Y axis from the fourthsliding convex portions 65 a and 65 b in the Y axial direction.Furthermore, the height position of the barycentric position G of theentire carriage 5 is substantially located on the same height positionas the second sliding convex portion 55 b (the second sliding surface52) and/or the fourth sliding convex portion 65 a, 65 b. In addition,the height position of the barycentric position G is substantially thesame as the height position in the Z axial direction (the verticaldirection) of the belt connecting part 63, and more detail, the heightposition of the barycentric position G is determined within the widthmeasurement of the timing belt 24 (refer to FIG. 11 and FIG. 12).According to these structures, even when the carriage 5 starts to movein the primary scanning direction (when the carriage 5 receives aneffect of acceleration, a moment around the Y axis passing through thebarycentric position G can be also supported on the side of the secondsliding convex portion 55 b (the second sliding surface 52). As aresult, it is possible to secure stable movement of the carriage 5 inthe primary scanning direction for the rotational moment of the carriage5 around the Y axis passing through the barycentric position G.

In addition, as shown in FIG. 4, FIG. 13, and FIG. 14, the carriage 5 issupported by one fist sliding convex portion 55 a and a pair of rightand left second sliding convex portions 55 b in the carriage 5 to beshaped in a triangle with respect to the first guide member 22 (thefirst sliding surface 51) and the second guide member 23 (the secondsliding surface 52) in a planar view, and further, the arrangementinterval X1 in the X axial direction of the right and left secondsliding convex portions 55 b is determined to be large. Therefore, thesupporting posture of the carriage around the Y axis passing through thebarycentric position of the carriage 5 is stabilized. Particularly, bymeans of action of the component force F4 in the X axial direction dueto the timing belt 24 when the carriage 5 starts to move in the primaryscanning direction (the X axial direction) (when the carriage moves froma resting state with acceleration), it is possible to effectivelyreceive a force that the carriage 5 intends to rotate around the Y axispassing through the belt connecting part 63 on the places of the pair ofright and left second sliding convex portions 55 b separated in rightand left and the second sliding surface 52. As a result, removing changeof the posture of the carriage 5 around the Y axis, it is possible tosecure stable movement in the primary scanning direction.

According to the present embodiment, the component force F5 in the Zaxial direction and the own weight of the carriage 5 among the componentforce F4 in the X axial direction and the component force F5 in the Zaxial direction of a tension F1 of the belt connecting part 63 againstthe timing belt 24 may act on the first sliding surface 51 of the firstguide member 22 and the second sliding surface 52 of the second guidemember 23 in a downward direction of the Z axis (vertically) via thefist sliding convex portion 55 a and the second sliding convex portions55 b (refer to FIG. 15). Then, as shown in FIG. 11, since a distance Y2along the Y axis from the barycentric position G of the carriage 5 up tothe first sliding convex portion 55 a and a distance Y3 along the Y axisfrom the barycentric position G of the carriage 5 up to the secondsliding convex portion 55 b are large, even when the carriage 5 comes torest and the carriage 5 moves in the X axial direction (the primaryscanning direction) at a predetermined rate, it is possible to stablysupport the carriage 5 by the first guide member 22 and the second guidemember 23 via the fist sliding convex portion 55 a and the secondsliding convex portions 55 b largely separated along the Y axis; the gapmeasurement (PG) between the lower surface of the recording head 4mounted on the carriage 5 and the sheet P on the platen 26 becomesstable, and thereby, the recording performance of the image is improved.

As shown in FIGS. 11 to 14, the third sliding surface 54 which isvertically arranged so as to be approximately orthogonal to the secondsliding surface 52 is disposed on the guide chip 23 c verticallyarranged in a vertical direction in the second guide member 23 so as tobe positioned between the first sliding surface 51 and the secondsliding surface 52 in the Y axial direction. The carriage 5 is providedwith the third sliding convex portions 60 a and 60 b which are slidableabutting against the third sliding surface 54 and the picking body 62which is an elastic member for elastically biasing the fourth slidingconvex portions 65 a and 65 b opposed to these third sliding convex 60 aand 60 b across the third sliding surface 54 (the guide chip 23 c). Thebelt connecting part 63 is located between the second sliding convexpart 55 a and the third sliding convex part 60 a, 60 b in the Y axis.According to this constitution, a rotational moment that the carriage 5intends to rotate around the X axis passing through the belt connectingpart 63 due to a tension of the timing belt 24 can be received when thethird sliding convex 60 a and 60 b disposed on the carriage 5 abutagainst the third sliding surface 54 in the vertical direction (the Zaxial direction). As a result, removing change of the posture of thecarriage 5 around the X axis, it is possible to secure stable movementin the primary scanning direction.

If the height position of the belt connecting part 63 is determined tobe higher than the position of the mounting portion (the driving pulley89 and the driven pulley 90) for the second guide member 23 of thetiming belt 24, particularly when the carriage 5 starts to move in theprimary scanning direction (when the carriage 5 moves from the restingstate with acceleration), the component force F5 in the verticaldirection of the tension of the timing belt 24 acts on the carriage 5 atthe position of the belt connecting part 63 in the carriage 5. In thiscase, the rotational moment that the carriage 5 intends to rotate aroundthe X axis passing through a gravity center can be effectively receivedon the second sliding convex portion 55 b (the second sliding surface51). As a result, removing change of the posture of the carriage 5around the X axis passing through the gravity center, it is possible tosecure stable movement in the primary scanning direction.

As shown in FIG. 4, FIG. 5, FIG. 7, and FIG. 8, the plurality offlexible ink supply tubes 20 a to 20 b for supplying the ink from theink storage part 15 disposed on the rest position of the main body ofthe apparatus 2 is connected to one side portion (the connection supportpart 61 b) opposed to the X axial direction of the carriage 5. When theplace where the ink supply tubes 20 a to 20 are connected to thecarriage (namely, a tube connecting portion 72) are positioned betweenthe fist sliding convex portion 55 a and the second sliding convexportions 55 b in the Y axial direction, a load in the vertical direction(the Z axial direction) is given to a connecting portion of the tubeconnecting portion 72 (namely, the connection support part 61 b). Themoment around the X axis passing through the gravity center G of thecarriage 5 due to this load can be also supported on the side of thesecond sliding convex portion 55 b (the second sliding surface 52). As aresult, removing change of the posture of the carriage 5 around the Xaxis passing through the gravity center, it is possible to secure stablemovement in the primary scanning direction.

In addition, in the Y axial direction, the place where the ink supplytubes 20 a to 20 are connected to the carriage (the tube connectingportion 72) is located between the second sliding convex portion 55 band the third sliding convex portions 60 a and 60 b. In other words,since the tube connecting portion 72 is located on the third slidingconvex portions 60 a and 60 b near the belt connecting part 63, themoment around the X axis passing through the gravity center G of thecarriage 5 due to the load when the ink supply tubes 20 a to 20 areconnected can be also supported by the second sliding convex portion 55b (the second sliding surface 52) and the third sliding convex portions60 a and 60 b (the third sliding surface 54). As a result, removingchange of the posture of the carriage 5 around the X axis passingthrough the gravity center, it is possible to secure stable movement inthe primary scanning direction.

Since the belt connecting part 63 of the carriage 5 along the Y axis isalso positioned between the fist sliding convex portion 55 a (the firstsliding surface 51) and the second sliding convex portions 55 b (thesecond sliding surface 52), particularly, by means of action of thecomponent force F5 in the Z axial direction due to the timing belt 24when the carriage 5 starts to move in the primary scanning direction(the X axial direction) (when the carriage moves from a resting statewith acceleration), it is possible to effectively receive a force thatthe carriage 5 intends to rotate around the X axis on the first slidingconvex portion 55 a (the first sliding surface 51) and the secondsliding convex portion 55 b (the second sliding surface 52). As aresult, removing change of the posture of the carriage 5 around the Xaxis, it is possible to secure stable movement in the primary scanningdirection.

Further, as shown in FIG. 14, the pair of right and left third slidingconvex portions 60 a and 60 b in the carriage 5 abut against the thirdsliding surface 54 of the guide chip 23 c in the vertical direction inthe second guide member 23 with a long interval X2 across the centerline OX in the X axial direction of the carriage 5. Further, in FIG. 13,the pair of fourth sliding convex portions 65 a and 65 b formed on theopposite ends of the picking body 62 is arranged on a symmetric positionat a distance for a measurement X3 across the center line OX in the Xaxial direction of the holder body 61 to elastically press the guidechip 23 c from its rear side. A force that the carriage 5 intends torotate around the Z axis passing through the belt connecting part 63 isgenerated by means of the action of the component force F4 in the Xaxial direction due to the timing belt 24 when the carriage 5 starts tomove in the primary scanning direction (the X axial direction) (when thecarriage moves from a resting state with acceleration). This force canbe effectively received on the pair of right and left third slidingconvex portions 60 a and 60 b separated right and left; the pair offourth sliding convex portions 65 a and 65 b; and the third slidingsurface 54. As a result, removing change of the posture of the carriage5 around the Z axis, it is possible to secure stable movement in theprimary scanning direction.

Next, the arrangement relation between the linear encoder and the inksupply tube and the constitution for maintaining a detection accuracy ofthe linear encoder will be described. The linear encoder according tothe present embodiment is an optical system and this linear encoder isformed by the tape scale 47 which is left at rest and the opticalpenetration sensor (the photo coupler) 61 c which is provided to thecarriage 5. As shown in FIG. 4, FIG. 5, FIGS. 8 to 13, and FIG. 16, theband-like tape scale 47 is extended as a long line along the X axialdirection on the upper surface of the second guide member 23 up to theopposite ends of the second guide member 23. The opposite ends of thetape scale 47 are supported by a supporting chip 86 lifted from theright and left opposite ends of the second guide member 23. Thisband-like tape scale 47 is arranged so that a detection surface (asurface where slits arranged at predetermined intervals in the X axialdirection are formed, not illustrated) follows a vertical direction.

On the other hand, on the upper surface of an upper cover 66 made of asynthetic resin to cover the upper surface of the holder body 61 in thecarriage 5, a shade wall 87 longer in the X axial direction having theguide groove 85 which is opened at its upper side so that the tape scale47 can pass through in the X axial direction and is opened also in the Xaxial direction is integrally formed. On the middle portion within theguide groove 85, the photo coupler 61 c as signal detecting means to beable to pass through across the front and rear surfaces of the tapescale 47 is arranged (refer to FIGS. 8 to 10). According to theabove-described constitution, the position of the carriage 5 from a homeposition (the right end of FIG. 4 according to the embodiment) and amoving rate when the carriage 5 reciprocates along the X axis aredetected.

The upper cover 66 detachable from the upper surface of the holder body61 is arranged over the upper surfaces of the storage part 61 a and theconnection support part 61 b. On the part in the upper cover 66 coveringthe storage part 61 a, a control substrate (not illustrated) foroutputting a predetermined driving signal to the recording head 4 isarranged in response to a signal sent from the flexible flat cable 40.Detachment of the upper cover 66 is necessary for maintenance such asexchange of the control substrate and the ink supply tubes 20 a to 20 dto be described later.

As shown in FIG. 8, a clearance groove (a concave portion) 88 having across section which is opened upward and formed in approximately aV-shape is integrally formed between the storage part 61 a and theconnection support part 61 b (more specifically, between the shade wall87 and the tube connecting portion 72 of the ink supply tubes 20 a to 20d) on the upper cover 66.

Next, the arrangement constitution of the ink supply tube 20 having aflexibility to always connect each ink cartridge 19 stored in the inkstorage part 15 to the recording head 4 in the recording part 7 will bedescribed in detail. According to the embodiment, respective ink supplytubes 20 a to 20 d are independent tubes made of a synthetic resinhaving flexibility.

As shown in FIGS. 3 to 5, FIG. 7, and FIG. 8, the plurality of inksupply tubes 20 (according to the embodiment, four) is elongated fromits one side end (a right end in FIG. 4) along the X axial direction ina direction of other end (a left end in FIG. 4) on the upper surface ofa lower cover body 29. In this case, root portions of the all ink supplytubes 20 a to 20 d are aligned in tandem in approximately a verticaldirection.

The middle portions of the all ink supply tubes 20 a to 20 d are bundledvia a movable wire-like bundling member 71 from the lower cover body 29up to the upper surface side of the second guide member 23. In the allink supply tubes 20 a to 20 d, their middle portions are curved and aretwisted, and their front ends are connected in approximately ahorizontal line on the connecting portion (the tube connecting portion72) which is disposed on one side of the connection support part 61 b(the left end in FIG. 4 and FIG. 5).

According to the present embodiment, the flexible flat cable 40 isprovided, which transfers a command signal allowing to selectivelyinject ink drops from the nozzle of the recording head 4 which ismounted on the carriage 5 from the control part (not illustrated) whichis disposed at the side of the main body of the recording apparatus 2.The flexible flat cable 40 is arranged on the area where the ink supplytubes 20 a to 20 d pass when the carriage 5 reciprocates in the X axialdirection (the primary scanning direction) approximately in parallelwith a direction of extension of the ink supply tubes 20 so that thewide surface of the flexible flat cable 40 is aligned in a verticaldirection (refer to FIG. 4 and FIG. 5). In addition, the curved portionof the flexible flat cable 40 is located inside of a radius of thecurved portions of the ink supply tubes 20 a to 20 d.

Since there is the above-described curved portions on the ink supplytubes 20 a to 20 d, due to a restoring force of the ink supply tubes 20a to 20 d such that the radiuses of these curved portions intent to belarger, a rotational moment around the Z axis acts on the tubeconnecting portion 72 and the carriage 5. This acting force can beeffectively received on the pair of right and left third sliding convexportions 60 a and 60 b separated right and left; the pair of fourthsliding convex portions 65 a and 65 b; and the third sliding surface 54.As a result, removing change of the posture of the carriage 5 around theZ axis, it is possible to secure stable movement in the primary scanningdirection.

The constitution for maintaining the detection accuracy of the linearencoder will be further described.

As shown in FIG. 7, an upper cover body 93, which is shaped in anapproximately rectangle in a planar view and is made of a syntheticresin, is detachably arranged on the upper surface of the recording part7. On the lower surface side of this upper cover body 93, a rib portion(partition) 94 as a partition wall is provided across the entire lengthof a moving range of the carriage 5 so that the tape scale 47 does notinterfere with the ink supply tubes 20 a to 20 d (they do not contactwith each other). This rib portion 94 has a triangle cross section whichis thin at the lower end side and becomes thicker toward the upper side.As shown in FIG. 9, FIG. 10, and FIG. 12, the side surfaces opposed tothe ink supply tubes 20 a to 20 d are formed on the inclined surfacewhich is directed to the downstream side in the subsidiary scanningdirection toward the upper side. The middle portions of the ink supplytubes 20 a to 20 d contacting this inclined surface are presseddownward, it is possible to reliably prevent contact with the tape scale47.

Further, the rib portion (partition) 94 as the partition wall is notnecessarily provided across the entire length of the moving rage of thecarriage 5. As long as the tape scale 47 and the ink supply tubes 20 ato 20 d act so that they do not interfere with each other (they do notcontact with each other), the rib portion 94 may be a portion(partition) which is provided on a part of the movement range of thecarriage 5.

When the carriage 5 moves (reciprocates) along the X axis, the curvedportions of the ink supply tubes 20 a to 20 d can be modified so thatthe radiuses thereof are made larger. The second guide member has aportion (an extension portion) including the horizontal wide chip 23 a,which is elongated from the taper portion including the guide chip 23 cup to the downstream side in the subsidiary scanning direction. When thecarriage 5 moves (reciprocates) along the X axis, a position of thepartial curved portion is moving on the upper side of the portion (theextension portion) including the horizontal wide chip 23 a. In such acase, the middle portions of the ink supply tubes 20 a to 20 d mayslidably contact the rib portion 94 (this may be a partition asdescribed above). Therefore, smooth movement of the ink supply tubes 20a to 20 d cannot be prevented. The surface of the tape scale 47 and theink supply tubes 20 a to 20 d do not contact with each other becausethey are blocked by the rib portion 94, and the detection accuracy ofthe linear encoder is not deteriorated (lowered) due to adhesion of theink to the tape scale 47. In addition, since the tape scale 47 passesthe upper surface side of the carriage 5, the tape scale 47 isvertically separated from the recording head 4 on the lower surface sideof the carriage 5. Therefore, it is difficult to adhere ink mistgenerated upon operation of recording the image on the surface of thetape scale 47, so that the detection accuracy of the liner encoder canbe maintained without deterioration. It is unnecessary for other wipercleaning to wipe the ink mist adhered to the tape scale 47 in otherwiper cleaning. Since the tape scale 47 does not contact the ink supplytubes 20 a to 20 d due to the rib portion 94, the oscillation generatedby the tape scale 47 when it contacts the ink supply tubes 20 a to 20 dis completely removed. Further, the detection accuracy due to the linearencoder is not deteriorated.

Then, when the carriage 5 is moving along the X axis, since theclearance groove 88 through which the rib portion 94 can pass is formedon the carriage 5, it is not necessary to arrange the upper cover body93 being largely separated from the upper surface of the carriage 5.Thus, there is an advantage such that the height measurement of theentire image recording apparatus 1 can be made smaller and the size ofthe apparatus is reduced.

In place of the above-described embodiment, according to anotherembodiment, the photo coupler 61 c as the place where the tape scale 47passes through and the signal detecting means is arranged between thepair of right and left third sliding convex portions 60 a and 60 b, thepair of fourth sliding convex portions 65 a and 65 b, and the tubeconnecting portion 72 in the sheet feeding roller, at the lower side ofthe carriage 5 which sandwiching the guide chip 23 c in verticaldirection in the second guide member 23, and on the lower surface sideof the connection support part 61 b. By forming the rib portion as thepartition wall which is shaped in a flat plate projected upward from thehorizontal wide portion 23 a in the second guide member 23 longer alongthe X axis, as same as an embodiment, it is possible to remove contactbetween the tape scale 47 and the ink supply tubes 20 a to 20 d. Thisembodiment also has a function as the partition wall that the secondguide member 23, which is having the horizontal wide chip 23 a and theupward guide chip 23 c, entirely prevents the ink mist in response toinjection of the ink from the recording head 2 from floating toward theside of the tape scale 47.

According to an embodiment, the apparatus can move in the primaryscanning direction as being supported by the opposite guide members onlyby the own weight of the carriage with respect to the first sidingsurface on the upper surface of the horizontal first guide member andthe second siding surface on the upper surface of the second guidemember.

Then, even if the curved portion at the middle portion is modified sothat the radius of the curved portion at the middle portion of the inksupply tube is made larger, the ink supply tube merely contacts thepartition wall, so that smooth movement of the ink supply tube cannot beprevented. Then, the surface of the tape scale does not contact to theink supply tube because they are blocked by the partition wall and thereis an advantage such that the detection accuracy of the linear encoderis not deteriorated (lowered) due to adhesion of the ink to the tapescale.

According to an embodiment, since the concave surface through which thepartition wall can pass is formed on the lower surface or the uppersurface of the carriage, the partition wall can be arranged in thevicinity of the lower surface or the upper surface of the carriage.Therefore, there is an advantage such that the height measurement of theentire image recording apparatus can be made smaller and the size of theapparatus is reduced.

According to an embodiment, since the tape scale passes through theupper surface side of the carriage, it can be said that the tape scaleis largely separated in a vertical direction from the recording headlocated on the lower surface side of the carriage and it is difficult toadhere the ink mist generated upon the image recording operation on thesurface of the tape scale. As a result, the detection accuracy of theliner encoder can be maintained without deterioration. In addition,since the tape scale does not always contact the ink supply tube due tothe rib portion as the partition wall, the oscillation generated by thetape scale when it contacts the ink supply tubes is completely removedand the detection accuracy doe to the linear encoder is notdeteriorated.

According to an embodiment, the tube connecting portion to the carriageof the ink supply tube is arranged on the downstream side in thesubsidiary scanning direction from the arrangement position of the tapescale, and the cross sectional shape of the rib portion in the uppercover body is formed on the inclined surface which is directed towardthe downstream side in the subsidiary scanning direction as at least theside on its downstream side is directed toward the upper side.

Accordingly, the middle portion of the ink supply tube contacting theinclined surface is pressed downward, so that there is an advantage suchthat contact with the tape scale can be reliably prevented.

According to an embodiment, the apparatus can move in the primaryscanning direction with the carriage supported by the first slidingsurface on the upper surface of the horizontal first guide member andthe second sliding surface on the upper surface of the second guidemember.

Then, the third sliding surface which is vertically arranged so as to besubstantially orthogonal to the second sliding surface is provided so asto be located between the first sliding surface and the second slidingsurface in the subsidiary scanning direction. The carriage is providedwith an elastic member for elastically biasing one pair of slidingconvex portions which can slide abutting against the third slidingsurface and other pair of sliding convex portions opposed to the onepair of the sliding convex portions across the third sliding surface ina direction of the third sliding surface. Therefore, the moment aroundthe vertical axis of the curved portion of the plural ink supply tubesconnected to one side portion of the carriage intending to be widenedcan be received by abutting one pair of sliding convex portions providedto the carriage against the third sliding surface in the verticaldirection (the Z axial direction), and it is possible to remove changeof the posture of the carriage around the vertical axis.

According to an embodiment, since the belt connecting part in thecarriage along the subsidiary scanning direction is positioned betweenthe second sliding surface and the third sliding surface, by means of atension of the no-end belt, particularly, when the carriage starts tomove in the primary scanning direction (when the carriage moves from theresting state with acceleration), the force that the carriage intends torotate around the axis in the primary scanning direction passing throughthe belt connecting part and the vertical axis can be effectivelyreceived on the second sliding surface and the third sliding surface. Asa result, reducing change of the posture of the carriage around the axisin the primary scanning direction and the vertical axis, it is possibleto secure stable movement in the primary scanning direction.

As this description may be embodied in several forms without departingfrom the spirit of essential characteristics thereof, the presentembodiments are therefore illustrative and not restrictive, since thescope is defined by the appended claims rather than by descriptionpreceding them, and all changes that fall within metes and bounds of theclaims, or equivalence of such metes and bounds thereof are thereforeintended to be embraced by the claims.

1. An image recording apparatus comprising: a recording head forrecording an image on a recording medium; an ink supply source forsupplying an ink to the recording head through an ink tube; a carriagefor mounting the recording head thereon, reciprocating in a primaryscanning direction; first and second guide members for supporting thecarriage thereacross and guiding reciprocating movement of the carriage,the second guide members being disposed downstream from the first guidemember in a subsidiary scanning direction perpendicular to the primaryscanning direction; a scale provided on the second guide member alongthe primary scanning direction; a detector provided on the carriage, fordetecting a reciprocating position of the carriage in corporation withthe scale; and a partition wall which is disposed in the vicinity of thescale and is not in contact with the scale, for separating at least apart of the ink tube from the scale.
 2. The image recording apparatusaccording to claim 1, wherein the carriage includes a concave portion towhich the partition fits with a gap.
 3. The image recording apparatusaccording to claim 1, further comprising a cover for covering at least areciprocating movement area of the carriage, wherein the partition isformed on the cover.
 4. The image recording apparatus according to claim3, wherein a cross section on a plane perpendicular to the primaryscanning direction of the partition is approximately a triangle of whichthe cover shares one side.
 5. The image recording apparatus according toclaim 3, wherein, in a cross sectional view of the partition on a planeorthogonal to the primary scanning direction, a length of a part sharedby the cover is larger than a length of a remote end from the cover, inthe subsidiary scanning direction.
 6. The image recording apparatusaccording to claim 5, wherein, in a cross sectional view of thepartition on a plane orthogonal to the primary scanning direction, aside downstream in the subsidiary scanning direction is a slope whichcomes into contact with the cover downstream from the remote end in thesubsidiary scanning direction.
 7. The image recording apparatusaccording to claim 3, wherein the partition provided along with anentire reciprocating movement range of the carriage in the primaryscanning direction is formed in a rib shape.
 8. The image recordingapparatus according to claim 1, wherein the ink tube has flexibility andhas a curved portion, and at least a part of the curved portion movesover the second guide member of the second guide member in response tothe reciprocating movement of the carriage.
 9. The image recordingapparatus according to claim 8, wherein a cross section on a planeperpendicular to the primary scanning direction of the partition isapproximately a triangle of which the cover shares one side.
 10. Theimage recording apparatus according to claim 8, wherein, in a crosssectional view of the partition on a plane orthogonal to the primaryscanning direction, a length of a part shared by the cover is largerthan a length of a remote end from the cover, in the subsidiary scanningdirection.
 11. The image recording apparatus according to claim 10,wherein, in a cross sectional view of the partition on a planeorthogonal to the primary scanning direction, a side downstream in thesubsidiary scanning direction is a slope which comes into contact withthe cover downstream from the remote end in the subsidiary scanningdirection.
 12. The image recording apparatus according to claim 8,wherein the partition provided along with an entire reciprocatingmovement range of the carriage in the primary scanning direction isformed in a rib shape.
 13. The image recording apparatus according toclaim 1, further comprising an enlargement which extends from thecarriage downstream in the subsidiary scanning direction, wherein thecarriage includes a concave portion to which the partition fits with agap, and the concave portion is formed in the enlargement of thecarriage.
 14. The image recording apparatus according to claim 1,wherein the partition is provided across an entire reciprocatingmovement range of the carriage in the primary scanning direction to beformed in a rib shape.
 15. The image recording apparatus according toclaim 1, further comprising: a first sliding surface extending from thefirst guide member in the primary scanning direction; an extensionportion formed in a flat shape which extends from the second guidemember downstream in the subsidiary scanning direction; a second slidingsurface provided on the extension portion of the second guide member inthe primary scanning direction, the first and second sliding surfacesbeing parallel to the primary scanning direction and the subsidiaryscanning direction; and a third sliding surface provided on the secondguide member approximately orthogonally to the second sliding surfacebetween the first and second sliding surfaces, wherein the carriagecomes into contact with the first, second, and third sliding surfaces;the carriage includes: a pair of sliding protrusions slidably abuttingagainst the third sliding surface; and another pair of slidingprotrusions opposing to the pair of sliding protrusions for pinching thethird sliding surface in corporation with the pair of slidingprotrusions; and the another pair of sliding protrusions includes anelastic member for biasing the third sliding surface.
 16. The imagerecording apparatus according to claim 15, wherein, with respect to aline passing through a center of the recording head in the subsidiaryscanning direction, one of the pair of sliding protrusions locatessymmetrically to the other of the pair of sliding protrusions, and oneof the another pair of sliding protrusions locates symmetrically to theother of the another pair of sliding protrusions.
 17. The imagerecording apparatus according to claim 1, further comprising: a firstsliding surface extending from the first guide member in the primaryscanning direction; an extension portion formed in a flat shape whichextends from the second guide member downstream in the subsidiaryscanning direction; a second sliding surface provided on the extensionportion of the second guide member in the primary scanning direction,the first and second sliding surfaces being parallel to the primaryscanning direction and the subsidiary scanning direction; a thirdsliding surface provided on the second guide member approximatelyorthogonally to the second sliding surface between the first and secondsliding surfaces; and a endless belt which is provided on the extensionportion along the primary scanning direction and to a part of which thecarriage is fixed through a fixing portion, wherein the carriage comesinto contact with the first, second, and third sliding surfaces, theendless belt is movable in the primary scanning direction, and thefixing portion locates between the second sliding surface and the thirdsliding surface in the subsidiary scanning direction.